Wednesday, March 31, 2010

Some Chalk Magic

Chalk is a supple, white, porous sedimentary rock, a form of limestone created of the inorganic calcite. It forms under somewhat deep marine situation from the stepwise accumulation of minute calcite plates (coccoliths) shed from micro-organisms called coccolithophores.
Chalk is resistant to withstanding and slumping contrasted to the clays with which it is generally associated.